Co-telomers and process for making them



CO-TELOMERS AND. PROCESS FOR MAKING THEM This invention relates to newfluorine-containing cotelomers and to a process for making them from adialkyl ether telogen and a mixture of at least two difierentpolyfluoromonoolefins, and particularly to liquid co-telomers that haveunusual properties which render them especially valuable for use ashydraulic fluids and as lubricants over a wide range of temperatures.

A serious problem facing lubrication engineers is to obtain materialswhich not onlyhave good lubricity and can take high loads, but whichshow hydrolytic, thermal and oxidative stability. It is known thatcompletely fluorinated hydrocarbons are exceedingly stable and that someof them have lubricating properties. However, they also have propertieswhich have seriously limited their utility, It has been proposed toprepare lubricants by complete fiuorination of hydrocarbon oils. This isUnited States Patent illustrated by the article by Struve et al. in Ind.and Eng.

Chemistry,vol. 39, No, 3 (March 1947.) pages 352 354, wherein theproduct is shown to have a very low viscosity index of -674, a very highviscosity of 536 centistokes at 100 F., the consistency of molasses whencold, and to contain solid fluorocarbons at temperatures below 50 C. 1 r

It has also been proposed to produce high fluorine-containing productsby the polymerization of fluorinecontaining olefins. In general, suchpolymers are solids. However, it has been found that if certainfluoro'olefins are polymerized in the presence of certain saturatedcompounds, called telogens, such compounds will react with end carbonsof the polymer chains before they have reached their maximumlength toterminate such chains and form compounds known as telomers. In manycases, the telomers are solids. However, in some cases, liquid telomersare produced which have been disclosed to have lubricating propertiesand to be useful as lubricants. Representative telomers, theirpreparation and their properties are disclosed by Miller et al. in Ind.and Eng. Chem, vol. 39, No. 3 (March 1947), pages 333 to 337. Suchtelomers contain unsaturation and loosely held chlorine and othergroups, whereby they are unstable and require an afteriluorinationtreatment to stabilize them. The stabilized telomers contain chlorinewhich decreases their stability at high temperatures and is reactivewith many metals, particularly copper, whereby they are corrosive athightemperatures. Also, such telomers have quite low viscosity indices andare liquid over a limited temperature range. In addition, telomers have,been prepared from tetrafluoroethylene and hydrocarbon telogens,including isobutane. Such telomers are greasy waxes or relatively 'lowboiling liquids having a limited liquid range.

Also, oo-telomers have been prepared from mixturesofchlorotrifluoroethylene and tetrafluoroethylene employing chloroformor carbon tetrachloride as the telogen. Such co-telomers also require anafter-fluorination to stabilize them. They are semi-solid at ordinaryroom temperatures and contain chlorine.

It is an object of thisinvention to provide novel,

fluorine-containing cotelomers, particularly such co- 2,907,795 PatentedOct. 6, 1959 2 telomers which areliquid over a more extended range oftemperatures, especially at very low temperatures, and which are stableandfnon-corrosive at high temperatures in the presence of water, oxygenand copper. A particular object is to provide co-telomers of suchcharacter which are high boiling liquids that have good lubricatingproperties at high loads as well as at low loads and which are speciallyuseful as lubricants at extreme ranges of temperature. Another object isto provide a simple one-step process for preparing such co-telomersfrom'low cost, readily available materials. Other objects are to providenew compositions of matter and to advance the art. Still other objectswill appear hereinafter.

The above and other objects may be accomplished in accord with thisinvention which comprises co-telomers l 1 wherein R is a member of thegroup consisting of fluorine, low'er perfluoroalkyl and loweromega-hydroperfluoroalkyl groups and each X is a member ofthe groupconsisting of fluorine and hydrogen; and to the process for preparingsuch co-telomers and other valuable products which comprises reacting,in the presence of a free radical catalyst, a telogen which is a dialkylether in which each alkyl radical contains 1-10 carbon atoms and, whenan alkyl group c'oritainsmore than 3 carbon atoms, a single hydrogenatom on at least one carbon atom, with a mixture of at least 2 differentpolytluoro-monoolefins of the formula r r R-'C=CX C it 1 wherein R isa'member of the group consisting of fluorine, lower perfluoroalkyl andlower 0mega-hydroperfluoroalkyl groups and each X is amember of" thegroup eons-isting of fluorine and hydrogen, said mixture contain ing atlea-st 29 mole percent of one polyfluoro-monoolefin and at least 29 molepercent of a dilterent po lyfiuoromonoolefin.

The process of this invention is simple andstraight'forward. The usualprocedure involves placing the desired amounts of the ether telogen, ofthe mixture of polyflu'oromonoolefins and of the free radical catalystinto a pressure reaction vessel and then closing the reaction vessel andheating to the desired reaction temperature while mechanically agitatingthe reaction vessel for several hours. The temperature at which thereaction is effected may be varied over a wide range depending primarilyupon the nature ofthe reactants, the catalyst, and the other conditionsof the reaction, in the manner known to the art in the preparationoftelomers. .Normally, the temperature will be in the-range of fromabout C. to about 200 C., preferably about llO C. Temperatures as low asabout 0 C. may be employed with a catalyst, such as trichloroacetylperoxide and trifluoroacetyl peroxide, which readily yield freeradicalsat such low temperatures. Temperatures materially above 200? C.contribute nothing to the reaction rate. For any par;

ticular charge, it is desirable to operate at a tempera 3 The productsof the reaction vary waxes, depending upon the ether telogen and thenumber and kind of polyfiuoro-monoolefins employed. The liquid productsare separated from the waxes by simple fractional distillation and, ifdesired, into definite fractions of limited boiling ranges. The olefins,employed in this invention, are the polyfluoro monoolefins of theformula wherein Risa member of the group consisting of fluofrom liquidsto 7 rine, lower perfluoroalkyl and lower omega-hydroperfluoroalkylgroups and each X is a member of the group consisting of fluorine andhydrogen. A polyfiuoromonoolefin'is used in its strict sense to mean anolefin which contains at least 2 fluorine atoms and only one unsaturatedbond that is an ethylenically unsaturated bond. Polyolefins, such asdiolefins, tend to produce unsaturated products. All of the fluorineatoms may be in R. However, when R is fluorine, at least one X must alsobe fluorine. A perfluoroalkyl group is an alkyl group in which allhydrogen atoms have been replaced by fluorine, i.e. it consists ofcarbon and fluorine. An omega-hydroperfluoroalkyl group is an alkylgroup in whichallhydrogen atoms, except a single hydrogen atom on theterminal carbon atom furthest removed from the double bond, have beenreplaced by fluorine. The term lower, as applied to the aforesaidgroups, means groups which contain at least 1 but not more than 4 carbonatoms. Representative polyfluoro-monoolefins, which are useful in thisinvention, include tetrafluoroethylene,

fluoro-monoolefins will be employed in about equimolecular proportion.-High yields of entirely satisfactory liquid co-telomers are obtainedwith such mixtures. However, it has been found that higher maximumyields of the higher-boiling liquid co-telomers are obtained when one ormore additional polyfluoro-monoolefins, particularly those in which atleast one X is hydrogen, are included in the mixture, i.e. when themixture contains at least 3 different polyfluoro-monoolefins, preferablywhen at least 2 of them are polyfluoro-monoolefins in which at least oneX is hydrogen. Relatively small proportions of the additionalpolyfiuoro-monoolefins produce large effects. For example, theproportion of highboiling liquid co-telomer in the reaction product isgreatly increased by the inclusion of about 0.1 mole of a thirdpolyfluoro-monoolefin in a mixture-of 0.5 mole of each of two otherdifferent polyfluoro-monoolefins.

The ether telogens, to be employed in this invention, are the dialkylethers in which each alkyl radical contains 1-l0 carbon atoms and, whenthe alkyl group contains more than 3 carbon atoms, a single hydrogenatomon at least one carbon atom, preferably when-the alkyl groupcontains more than 2 carbon atoms. In other words, when an alkyl groupcontains more than 3 carbon atoms, at least 1 of the carbon atoms mustbear a single hydrogen atom, that carbon atom being otherwise bonded to3 hexafluoropropene, vinylidene fluoride, trifluoroethylene, 1:

3,3,3 -trifluoropropene-1, perfluorobutene-l, perfluoropentene 1,perfluorohexene-l, omega hydroperfluorohexene-l,1,3,3,3rtetrafluoropropene-l, 2,3,3,3-tetrafluoropropene-l,1,1,3,3,3-pentafluoropropene-1, 1,2,3,3,3-pentafluoropropene-l,3,3:difluoropropene-l, and the like.

.Inorder to obtain the advantageous results, and the valuableco-telomers' of this invention,.it is essential to use a mixtureof. atleast two different polyfluoromonoole- -fins of the specified structurein the process. Such mixture should contain at least 29 mole percent ofone poly--' fluoro-monoolefin and at least 29 mole percent of adifferent polyfluoro-monoolefin, the rest of the mixture (42 molepercent) being composed of either or both of those twopolyfluoro-monoolefins or, in whole or in part,

of one or more other polyfluoro-monoolefins of the struc-* turehereinbefore specified. The mixture may be composed wholly ofpolyfluoro-monoolefins in which each X perfluoro-monoolefins. However,it is much preferred that the mixture include at least onepolyfluoro-monoolefin inwhich at least one X is hydrogen in a proportionof at least 29 mole percent of the mixture. It has been found that, inthe latter case, there is obtained significantly higher yields ofhigh-boiling liquid co-telomers and that such high-boiling liquids havelower pour points and a more extended liquid range, than when themixture is composed wholly of polyfluoro-monoolefins in which each X isfluorine. Itv is further preferred that the mixture contain at least 39mole percent of a polyfluoromonoolefin in which at least two X arefluorine, especially one in which each X is fluorine, and at least 29mole percent of a different polyfluoro-monoolefin in which at least oneX is hydrogen, especially one in which two X are hydrogen.

The mixture of polyfluoro-monoolefins may consist of only two members ofthe class. Generally, such mixture will contain from about 29 to about71 mole percent of one of the polyfluoro-monoolefins and from about 71to about 29 mole percent of the other, preferably about 39 to about 71mole percent of one and about 61 to about '29 mole percent. of the.other. Usually, the two polycarbon atoms (i.e. a tertiary carbonatorn'as in-di-isobutyl ether) or to 2 carbon atoms and the etherealoxygen atom as in di-secondary-butyl ether (equivalent to a tertiarycarbon atom) When the alkyl group contains rnore than 6 carbon atoms atleast 2 of them, preferably 3 of them, should bear a single hydrogenatom. -On-the other hand, when the alkyl radical contains 1-3 carbonatoms, it is not necessary that any carbon atorn'thereof bear a singlehydrogen atom. However, a carbon atom bearing a single hydrogen atom ispreferably present also-when the alkyl group contains 3 carbon atoms, asin the isopropyl radical, for ease of reaction and significantlyincreased yields of desired products. The preferred telogens are thedialkyl ethers in which each alkyl radical contains 3-6 carbon atoms atleast one of which bears a single hydrogen =atom. Representative dialkylethers whichare useful as telogens in this invention are di-methylether, di-ethyl ether, methyl ethyl ether, dim-propyl ether,di-isopropyl ether, methyl-n-propyl ether, methyl isopropyl ether, ethylisopropyl ether, di-isobutylether, di-secondary-butyl methylsecondary-butyl ether, di-isoamyl ether, bis(1, 2-

' dimethyl-propyD-ether, di-isohexyl ether, isopropyl isohexyl ether,ethyl isohexyl ether, bis(diisopropylmethyl) ether,bis(triisopropylmethyl) ether, and the like. 'Diisopropyl ether is mostpreferred.

It appears that, in the course of the reaction, thepolyfluoro-monoolefins copolymerize to form polymer chains composed of 2or more different polyfluoro units and that such polymer chains reactwith the telogen. Thus, thepolymer chains contain. at least 2 polyfluorounits and may contain a total of ,up toabout 25 polyfluoro units,including one or more of each of the different polyfluoro units. Thepolymer chain replaces a hydrogen atom of the telogen and becomesterminated at its free end by a hydrogen atom. Usually, only onehydrogen atom of the telogen is replaced by one such polymer chain. Insome cases, a small proportion (usually less than 1% by weight) of theproduct may have two or more hydrogen atoms of thetelogen replaced bypolymer chains. Single hydrogen atoms (on tertiary carbon atoms or'their equivalents) are most easily replaced andhence, when an alkylgroup contains a single hydrogen atom, that hydrogen atom ispreferentially replaced bythe polymer chain. When an alkyl groupcontains more than 1 replaceable hydrogen atom, one of these hydrogenatoms isreplaced by a polymer chain composed of two or more-differentpolyfluoro units, and one or more other yhydrogen atoms all atom whichis otherwise singly bonded to elements other than hydrogen, and (2) apolymer chain satisfying the valence of the ether radical, said polymerchain being terminated at its free end by a hydrogen atom and otherwiseconsisting of at least two different polyfluoro units of the structurewherein R is a member of the group consisting of fluorine, lowerperfluoroalkyl and lower omega-hydroperfluoroalkyl groups andeach X is amember of the group consisting of fluorine and hydrogen, said polymerchain preferably including at least 1 polyfluoro unit in which at leastone X is hydrogen. It is particularly desirable that the polymer chainconsists essentially ofat least 1 polyfluoro unit in which each X isfluorine and at least 1 polyfluoro unit in which at least one X ishydrogen. At times, there is obtained a small amount of low boilingtelomers of the individual polyfluoro-monoolefins. However, the greatmajority of the products are cotelomers of this invention which containbetween 23% and 70% by weight of fluorine and a single polymer chainwhich contains at least 2 different polyfluoro units. The co-telomersshow no unsaturation when tested with permanganate and are stable athigh temperatures, hence do not require any after-fluorination tostabilize them. The liquid co-telomers, particularly the high-boilingliquids, are especially valuable and are obtained in high yields whereasthe yields of the less valuable waxes are low. The liquid co-telomershave utility as non-flammable, non-corrosive hydraulic fluids, assnuffer agents for flammable solvents, and as lubricants. They arethermally and chemically stable and have an unusually extended liquidrange, i.e. have low pour points and high boiling points and are free ofsolid polymeric products, whereby they are useful at extremes oftemperature at which other hydraulic fluids and lubricants lose theirutility. As lubricants, they have good lubricity and can take unexpectedly high loads, and have higher viscosity indices than priorhighlyfluorinated lubricants. The waxes are useful as lubricants, mold releaseagents, as protective coatings for var-ions surfaces, and as impregnantsfor paper and textile materials to render them water and oil 'repellant.The preferred co-telomers of this invention are the normally liquidco-telomers which contain from about 60% to about 61% by weight offluorine, boil in the range of from about 200 C. to about 310 C., andconsist of of the monovalent radical of di-isopropyl ether in which thevalence belongs to one of the carbon atoms which is bonded to oxygen anda polymer chain satisfying the valence of the monovalent radical, saidpolymer chain being terminated at its free end by a hyd'rogenatom andothenwise consisting essentially of at least one unit of the structure 1OF CF and at. least, one unit of the structure -CF CH Such co-telomersare the products of the reaction of di-isopropyl ether, as a telogen,with a mixture of polyfluoro-monoolefins which mix ture consistsessentially of about equi-molecular proportions of tetrafluoro -ethyleneand vinylidene fluoride, including such mixture ofpolyfluoro-monoolefins containing about 0.1 mole of3,3,3-trifluoro-propene-1. The preparation of such co-telomers isillustrated by Examples 3 and 4 given hereinafter.

' The ratio of telogen to the mixture of polyfluoro-monoolefins may varyconsiderably, and the range thereof corresponds to the knownrange ofratios. of telogen to polyfluoroolefinsconventionally employed in thepreparation of telomers of the prior art. Generally, the telogen canvary from at least about 0.1 mole up to about 20 moles for each mole ofthe mixture of polyfluoro-monoolefins, preferably from about 1.5 toabout 5 moles of telogen for each mole of polyfluoro-monoolefins to givehigh yields of high boiling liquids and little or no low boilingproducts. Excess telogen serves as a solvent for the reactants and, ingeneral, is not objectionable so long as it does not result in too highdilution of the reactants or unduly increase the costs of the subsequentsteps of separating and recovering the ingredients of the reactionmixture,

The catalyst should be a free radical catalyst, i.e. a compound whichreadily yields free radicals. Such catalysts are well known,particularly for. the preparation of telomers of polyfluoro-olefins. Thecatalysts include peroxygen compounds, such as ditertiary butylperoxide,

diacyl peroxide, benzoyl peroxide, ethyl peroxide, sodium peroxide,hydrogen peroxide, oxygen, ozone, and ammonium persulfate. Also,included are tertiary butyl hydroperoxide, peracetic acid, diacetylperoxide, trichloroacetyl peroxide, trifluoroacetyl peroxide, and thelike. The preferred catalyst is ditertiary butyl peroxide. The selectionof the catalyst will influence somewhat the temperature atwhich thereaction will be carried out, since a temperature should be used whichwill insure the efficient generation of free radicals and a half-life tothe catalyst of about four hours. The amount of the catalyst employedwill correspond with that which is known to be useful in the preparationof telomers of polyfluoroolefins, and in accord with the knownprinciples in connection therewith. Generally, the catalyst may be fromabout 0.1% to about 10% by weight based on the weight of the telogen,preferably from about 0.8% to about 10 The lower ratios of catalyst,below about. 5, give lower conversions but higher proportions of thehigher boiling liquids in the products, whereas the higher ratios ofcatalyst, 5% and above, give higher conversions but lower proportions ofthe higher boiling liquids.

The reaction may be carried out at atmospheric pressures or atsuper-atmospheric pressures. Usually, autogenous pressures will be used,generally of the order of to 1,000 pounds per square inch gauge.Externally induced pressures up to about 10,000 pounds per square inchgauge ean be used, but generally without significant improvement. s

In order to more clearly illustrate this invention, preferred modes ofpracticing it, and advantageous results to be obtained thereby, thefollowing examples are given, wherein the parts are by weight exceptwhere otherwise specifically indicated:

EXAMPLE 1 A stainless steel agitated reaction vessel is charged with 100parts (2.17 moles), of dimethylether, 50 parts (0.5 mole) oftetrafluoroethylene, 38 parts (0.5 mole) of vinylidene fluoride, and 6parts (0.04 mole) of ditertiary butyl-peroxide catalyst. The reactionvessel is then closed, heated to C. and held at 110 C. for 2.5 hoursduring which time the pressure drops from about 850 p.s.i.g. to about475 p.s.i.g. After cooling and opening the reaction vessel, 89 parts ofan opaque White liquid is obtained which on distillation yields thefollowing fractions:

B oiling Percent of Total Range 35145 C. -300 C. Greasy Wax.

H5002 New.

.2 .2 0,. i s s .6

Fractions 7 The above fractions are redistill ed to give cuts having thefollowing analysis: I w

The analysis of cut #3 indicates that this product contains 1 to 3tetrafluoroethylene units and vinylidene fluoride units per molecule.

- When the above experiment is repeated but the reaction allowed toproceed for 12 hours at 75 C. and at 150C. for 1 hour, essentially thesame results are obtained... 1

The crude product may be purified if desired. It is often advantageousto wash it With concentrated nitric acid followed by a wash withconcentrated sulfuric acid or a mixtureof these acids. The use of theseacids either cold or warm will assist in removing fragments of catlystthat may remain. As indicated, the product can be distilled andfractionated at atmospheric or reduced pressures. Often, it is desirableto filter the liquids through alumina to remove some color residue whichoften persists from catalyst fragments.

On refluxing the liquids of cuts #2 and #3 above for 100. hours incopper flasks and in contact with air, there is no corrosion of thecopper, no detectable acidity in the liquid and only very slightdiscoloration. When cut #4 is held at 250"v C. under the same condition,no corrosion, acidity or significant discoloration is observed.

EXAMPLE 2 Following the general procedure and conditions of Example 1,150 parts (3.25 moles) of dimethyl ether, 20 parts (0.208 mole) of3,3,3-trifluoropropene-l, 50 parts (0.5 mole) of tetrafluoroethylene and6 parts of ditertiary butyl peroxide are reacted for 6 hours at 110 'C.In this ,way, 82 parts of liquid product are obtained which ondistillation yields:

A. 56.2% boiling at 62-190 C. B. 27.4% boiling at 190260 C. C. 12.3%boiling at 260-310 C. D. 4.1% greasy wax On heating these liquids incopper flasks (for 100 hours in the presence of air and at 250 C. (or atreflux), no significant change occurs.

EXAMPLE 3 Following the general procedure of Example 1, 180 parts (1.76moles) of diisopropyl ether, 50 parts (0.5 mole) of tetrafluoroethylene,38 parts (0.5 'mol'e) of vinylidene fluoride and 6 parts of ditertiarybutyl peroxide are heated at 110 C. The initial pressure of 700 p.s.i.g.is increased to. about 8000 p.s.i.g. by pressuringwith nitrogen. After 3hours, the reaction vessel is cooled,

for 7 hours.

and the product, 249 parts of colorlessxliquid, is removed and distilledto yield the following fractions: A. 65.7% boiling at ZOO-310 C.

. q B. 34.3% greasy wax q A cut, having a boiling range of C./0. 15 mm.

Hg to C./ 0.10 mm. Hg, was found to have an average molecular weight of604. An elemental analysis indicated it to have the structure:

Analysis of a cut boiling at 3003l0 C. shows that it contains 34.7% C,2.8% H, and 60.1% F. It has an average molecular weight of 760 and has apour point of 60 C. g

The wax fraction contains 32.9% C, 2.6% H, and 62.2% F. A distilled waxfraction dissolves in amyl acetate to give a solution containing between15% and 20% by weight of the wax. Such solution is readily ob.- tainedby heating under reflux for a short time.

When the liquid product was held at 250 C. for 100 hours in a copperflask and in the presence ofair, no corrosion occurred.

By way of comparison, when a mixture of 100 parts of diisopropyl ether,50 parts of tetrafluoroethylene and 2 parts of ditertiary butyl peroxidewere similarly reacted at 110 0, there was obtained 33.7 parts of aliquid material which freezes at about 5 C. and has a boiling range of60 C./8 mm. Hg to 157 C./0.9 mm. Hg. Part v EXAMPLE 4 Following thedetails of Example 1, parts (1.76 moles) of diisopropyl ether, 50 parts(0.5 mole) of tetrafluoroethylene, 38 parts (0.5 mole) of vinylidenefluoride, 10 parts (0.104 mole) of 3,3,3-trifluoropropene-l, and 6 partsof ditertiary butyl peroxide are reacted at 110 C. The initial pressureof 650 p.s.i.g. drops to 290 p.s.i.g. during the reaction. The productof 272 parts of clear, colorless liquid is distilled to yield 82.5% ofliquid boiling at ZOO-310 C. and 17.5% of greasy wax. A liquid cutboiling at 260310 C. and having a pour point of 68 C. contains 36.1% C,3.4% Hand 61.2% F. This material shows no corrosionto copper after 100hours at 250 C. and in the presence of air.

EXAMPLE 5 A. 32.3% boiling at 80-180" C. B. 53.1% boiling at 20O320 C.C. 4.6% greasy wax 1 Analysis of a cut boiling at 260-300 C. shows thatit contains 35.2% C, 3.0% H, and 61.1% F. This liquid has a pour pointof -40 C. This liquid is stable to copper and air at 250 C. for over 100hours.

EXAMPLE 6 -Followii1g the details of Example.l,- 180' parts (1.76

moles) of diisopropyl ether, 50 parts (0.5 mole) of tetrafluorqethylene,'50 parts (0.33 mole) of hexafluoropropene 74.5% boils at80 165? c. 21.0% boils at,165-2 C. 1.7% boils; at zoo-25o" c. 2.8% is agreasy wax.

Analysis of a cut boiling at 200-250 C. shows that it contains-323% C,2.5% H, and 63.8% F. The liquid has a pour point of 0 C. and shows nosignificant decomposition at 250*6. for over 100 hours in the presenceof copper and air. i It is also wellk nownthat liquidtelomer products,which have beenproposed for use as lubricants, have been prepared fromchlorotrifiuoroethylene, employing chloroform or carbon tetrachleride asthe telogen and then aftertreating the product byfluon'nation with Golto remove unsaturation and other loosely held substituents and tostabilize the product. The properties of a representative,commerically'available product (oil C) so prepared are compared in thefollowing Table I with representative products (oils and B) of 'thisinvention prepared by the processesof Examples 3' and 4grespectively:

Table I Therm. Stab. Corro- Pour BoiL- inAir Decomp. ,slon Oil 1 V.I..Point, Range, Prod; on On, 1 g. O; 250C.

AA... 87 i 60 290-.310' Eric... Exc. none... none.

18-.-- -68 260-310 Eire.-. Exc... none.. none. C-. 181 --15 250-300Exc.-- 6hrs whiite pitting.

posit.

It should be noted that oil Chas aliquid range from -15to*300 C. whereasoil A isliquid from '6 0 to 310 C. and oilB is-liq uid from -68 C. to310 C. This is 55 to 63*eentigr adedegrees, or about17.5% to 20%greater. All three oils are thermally stable (Exc) in air at 200 C. andshowed no color change. Fur= thermore, oils A and B have excellent (Exe)thermal stability at 250 C., whereas oil C breaks down in 6 hours atthis temperature. In addition, no decomposition products appear i'n oilsA or'B but oil C develops white deposits. Alsoof great significanceisthe fact that oil C causes jpitting oncopper at 250 C.,while oils Aand B show nofcorrosioh. Furthermore, oil A has a much higher viscosityindex (V.I.) than oil C.

One ot the requirementsofan acceptable lubricant is that it withstandthe load towhich it is subjectedunder use. "That is, the lubricatingfilm which separates the moving bearing surfaces must not be broken. Thegreate1- theload on the bearing surfaces the greater must be the filmstrength of the lubricant. it The lubricants of 'thisinventi on haveexceptionally good strength under high" loads as shown by the Almen filmstrength test. test consists ofkrotating a steel cylindrical rod in asteelsplit bushing while the entire assembly is immersed in the testoil. Two-pound weights are added at ten second intervals as the rod r0-ft s at 20 Ii -m eh s t b ar n l d a ich seizure occnrsis recorded.Al-u'bricant film which can Withstand abearingload exceeding about10,000 psi. is considered to be very good. The data in the followingTable II indicate the excellentfllm strength of the. lubrioants of thisinvention in which a representative co'telother (A), fraction AofExarnple 3 havinga boiling r'angeof 200-310 C., is compared towell-knownliquid lubricants: i

Table-Il Almen Film Strength Lubricant 2,000 r.p.m.Slldlng speed 39ft./min.

Psi. (Jo-telomerA 15,000 Mineral lubricating oi1 6,000 Di(2-ethyl hexylsebacate) ;.L 6, 000 lPerfluorocarbon-oil 3,000

1 Obtained by fluorination of a hydrocarbon oil with cobalt trifluoride.

The low boiling liquids otthis invention are useful also as hydraulicfluids [under those conditions where extremely low temperatures normallycause the oil, to solidify and, becomeofi little. value. The liquids ofthis inventionare alsonseiul toincrease flash points of flamrnablesolvents (shutter. agents). Merely mixing the solvent with a smallproportion, ofv the order of 1% by weight, of the co-telorner oilresults in a significant flash point increase. t t i In s m ca es pro ro f a -t m a is obtained. finch. is 'more soluble in amyl acetate andlike organic solvents than the solid telorners of single polyfluoromonoolefins. Thereby, the co-telomer waxes of this invention areparticularly adapted to be applied, in the form of solutions in amylacetate and like solvents, as protective coatings to surfaces and asimpregnants for paper, textiles, and like materials to render them waterand oil repellent.

It will be understood that Examples} to 6, inclusive, are given forillustrative. purposes solely, and that this inventionis not restrictedto the, specific embodiment-s disclosed therein. On the other hand, itwill be readily apparent tothosefskilledfin the art that, within, the.limits set forth in. the] general description, many variations andmodifications can be made without departing fronrthe spirit and scope.of this invention. For example, the mix.- tures ofpolyfluoro-monoolefins may beeornposed of other polyfluoro-monoo1efinsof the class, a greater number of such.polyfluorofmonoolefins, otherproportions of the different polyfluoro-monoolefins to each other, andthe like, with corresponding variations in the structure and the numberof polyfluoro units in the polymer chains of the co-telorners. Likewise,the dialkyl ether telogens may be varied. to vary, to some extent, thehydrocarbon portion of the co-telomer. Furthermore, the catalysts, theproportions thereof, the temperatures, the other conditions, theapparatus, and the techniques employed may be widely varied.

From the preceding description, it will be apparent that this inventionp vides a s mp e, oneep p o es fo readily preparing novel,saturatedpolyflnoro co-telomers Particularly, this inventionprovides new compositions of matter which are co-telomers which have novel, veryvaluable advantageous properties and utilities. Accordingly, thisinvention constitutes a valuable contribution to and advance in the Thisis a continuation-impart of my copending application Serial No. 516,309,filed June 17, 1955, now abandoned. t

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows: e

A ted c -te ms on ain ng between 3% and 70% "by weight of fluorine andconsisting of (1) a radical of a dialkyl ether which contains at leastone hydrogen atom on at least one of the carbon atoms that is bonded tothe ether oxygen atom and in which each alkyl group contains 1-10 carbonatoms, including, when the alkyl group contains 4- 10 carbon atoms, atleast 1, wise consisting of a total ofyabout 4.0 to about 25 units oftwo to three different polyfluoro units of the structure R X X it Iwherein R is a memberof the group consisting of fluorine, lowerperfluoroalkyl and lower omega-hydroperfluoroalkyl groups and each X isa member of the group consisting of fluorine and hydrogen at least one Xbeing fluorine when R is fluorine.

2. A normally liquid saturated co-telomer containing between 23% and 7%"by weight of fluorine andconsisting of (1)a radical of a dialkyl etherwhich contains at least one hydrogen atom on at least one of the carbonatoms that is bonded-to the ether oxygen atom and in which each alkylgroup contains 3-6 carbon atoms and in which at leastone carbon atomwhich is bonded to no more than one hydrogen; atom, and (2) a polymerchain satisfying the valence of the ether radical, said polymer chainbeing terminated at the free end by a hydrogen atom and otherwiseconsisting of a total of about 4.0 to about 25 units of two to threedifferent units of the structure v t v R l I l V i i. wherein'R is' amember of the group consisting of fluor-ine, lower perfluoroalkyl andlower omega-hydroperfluoroalkyl groups and each X is a member of thegroup consisting of fluorine and'hydrogen at least one X being fluorinewhen R .is fluorine, including at least 1 polyfluoro unit inwhich'atleast one X is hydrogen. I f 3. A normally liquid saturated co-telomercontaining between 23% and 70% by Weight of fluorine and consisting of(1) a radical or a dialkyl ether which contains at least one hydrogenatom on at least one of the carbon atoms that is bonded to theetheroxygen atom and in which each alkyl group contains 3-6 carbon atoms andinwhich at least one carbon atom which is bonded to no more than onehydrogen atom, and (2)"a polymer chain satisfying the valence of theether radical, said polymer chain being terminated atthe free end by ahydrogen atom and otherwise consisting'of a totalof about 4.0 to about25 units of two to three different poly fluoro units of the structure Iwherein R is a member of the group consisting of fluorine, lowerperfluoroalkyl and lower omega-hydroperfluoroalkyl groups {and each X isa member of the group consisting of fluorine and hydrogen at least one Xbeing fluorine when Ris fluorine, said polymer chain consistingessentially of atleast 1 polyflluoro unit in which each X is fluorineandat least 1 polyfluoro unit in which at least one X'is hydrogen. I

' 4. A saturated'co-telomer containing between 23% and 65% by weightoffluorine and consisting of (1) the radical of di-isopropyl ether inwhich the valence belongs to one of the carbon atoms which is bonded tooxygen, and (2) a polymer chain satisfying the valence of the etherradical, said polymer chain being terminated at' the free end byahydrogen atom and otherwise consisting of a total of about 4.0 to about25 units'of two to three different polyfluoro units of the structure allI a t l i I v wherein R isa member of the group consisting of fluo rine,lower perfluoroalkyl andlower omega-hydroperfluoroalkyl groups and eachX is a member of the group. consisting of fluorine'and hydrogen at leastone X bein fluorine when R is fluorine.

5. A normally liquid saturated co-telomer containing from about 60% toabout 61% by weiightof fluorine and boiling in the range 'of' about 200C. to about 310 C. and consisting of ('1) the radical of'di-isopropylether in which the'valence belongs to one of the carbon atoms that isbonded to oxygen, and (2) a polymer chain satisfying the :valence. ofthe ether radical, said polymer chain being terminated at the free endby a hydrogen atom and otherwise consisting essentially ofat least oneunit of the structure --CF --CF and at least oneunitof, the structure CF--CF a 6. The process for; preparing co-telomers containing between 23%and 70%v by weight of fluorinewhich com? prises telomerizing, in thepresence of a free radical telomerization catalyst, a dialkyl etherwhich contains-at least one hydrogen atom on at least one of the carbonatoms that is bonded to the ether oxygen atom and in which each alkylradical contains 1-10 carbon atoms, including, when the alkyl groupcontains 410 carbon, atoms, at least one carbon, atom bonded to no morethan one hydrogen atom, with a mixture of 2 to 3 dilferentpolyfluorornonoolefins ofthetormula RC==CX wherein R is a member of thegroup consisting of fluo-' rine, lower perfluoroalkyl and loweromega-hydroper- I fluocroalkyl groups and each X is a member of thegroup consisting of fluorine and hydrogen at'least one X being fluorinewhen R is fluorine, said mixture containing at least 29 mole percent ofone polyfluoro-monoolefin and at least 29 mole percent of a difierentpolyfluoro-mono olefin. 7. The process for preparing co-telomerscontaining between 23% and 70% by weight of fluorine which corn: prisestelomerizing, in the presence of a free radical telomerization catalyst,a dialkyl ether which contains at least one hydrogen atom on at leastone of the carbon atoms that is bonded to the ether oxygen atom and inwhich each alkyl radical contains 3-6 carbon atoms and at least onecarbon atom bonded to no more than one hydrogen atom with a mixture of 2to 3 polyfluoro-monoolefins of the formula v RC=GX it X wherein R is amember of the group consisting of fluw rine, lower perfluoroalkyl andlower omega-hydroperfluoroalkyl groups and each Xis a member of thegroup consisting of fluorine and hydrogen at least one X being fluorinewhen R is fluorine, said mixture containing at least 29 mole percent ofa poly-fluoro-monoolefin in which at least two X are fluorine and atleast 29 mole percent ofa difierent polyfluoro-monoolefin in which atleast one X is hydrogen. I r

, 8. The process for preparing oo-telomerscontaining between 23% and 70%by weight of fluorine which com prises telomer'izing, in the presence ofa free radical telomerization catalyst, di-isopropyl ether with amixture of 2 to 3 polyfiuoro-monoolefins of the formula if R-O=CX"first" wherein R is a memberfof the group consisting of fluorine, lowerper-fluoroal kyl and lower "omega-hydropei'r fluoroalkyl groups and eachX is amernber of the group consisting of fluorine and hydrogen at leastone X being fluorine when Ris fluorinepsaid mixture, containing at least29 mole percent of a polyfluorovmonoolefin in which 'at least two Xarefluorine and at least 29 mole percent of a differentpolyfluoro-monoolefin in'which at least one X is hydrogen.

9. The process for preparing co-telomers containing between 23% and 70%by weight of fluorine which comprises telomerizing, in the presence of afree radical telomerization catalyst, di-isopropyl ether with a mixtureof 2 polyfluoro-monoolefins of the formula wherein R is a member of thegroup consisting of fluorine, lower perfluoroalkyl and loweromega-hydroperfiuoroalkyl groups and each X is a member of the groupconsisting of fluorine and hydrogen at least one X being fluorine when Ris fluorine, said mixture consisting of from about 39 to about 71 molepercent of at least one polyfluoro-monoolefin 'in which each X isfluorine and from about 61 to about 29 mole percent of at least onepolyfluoro-monoolefin in which at least one X is hydrogen.

10. The process for preparing a normally liquid satmated co-telomercomposition containing about 60% fluorine and boiling in the range ofabout 200 C. to about 310 C. which comprises telomerizing, in thepresence of a free radical telomerization catalyst, di-isopropyl etherwith a mixture of polyfluoro-monoolefins which consists essentially ofabout equi-molecular proportions of tetrafluoroethylene and vinylidenefluoride.

References Cited in the file of this patent UNITED STATES PATENTS2,433,844 Hanford Jan. 6, 1948 2,471,959 Hunt May 31, 1949 2,598,283Miller May 27, 1952 2,694,701 Blllm et a1. Nov. 16, 1954 2,775,618Dittman et a1 Dec. 25, 1956 2,856,440 Wolif Oct. 14, 1958 FOREIGNPATENTS 583,874 Great Britain Jan. 1, 1947 UNITED STATES PATENT OFFICECERTIFICATE OF CORRECTION Patent Nou 2,907,795 October 6, 1959 NikolausE. Wolff It is hereby certified that error appears in the-printedspecification of the above numbered patent requiring correction and thatthe said Letters Patent should read as corrected below.

Signed and sealed this 19th day of April 1960 (SEAL) Attest:

KARL HQIAXLINE ROBERT C. WATSON Attesting Oflicer Commissioner ofPatents

1. A SATURATED CO-TELOMER CONTAINING BETWEEN 23% AND 70% BY WEIGHT OFFLOURINE AND CONSISTING OF (1) A RADICAL OF A DIALKYL ETHER WHICHCONTAINS AT LEAST ONE HYDROGEN ATOM ON AT LEAST ONE OF THE CARBON ATOMSTHAT IS BONDED TO THE ETHER OXYGEN ATOM AND IN WHICH EACH ALKYL GROUPCONTAINS 1-10 CARBON ATOMS, INCLUDING, WHEN THE ALKYL GROUP CONTAINS4-10 CARBON ATOMS, AT LEAST ONE CARBON ATOM WHICH IS BONDED TO NO MORETHAN ONE HYDROGEN ATOM, AND (2) A POLYMER CHAIN SATISFYING THE VALENCEOF THE ETHER RADICAL, SAID POLYMER CHAIN BEING TERMINATED AT THE FREEEND BY A HYDROGEN ATOM AND OTHERWISE CONSISTING OF A TOTAL OF ABOUT 4.0TO ABOUT 25 UNITS OF TWO TO THREE DIFFERENT POLYFLUORO UNITS OF THESTRUCTURE